Tegan Jovanka was an Australian air stewardess trainee who wandered into the Fourth Doctor's TARDIS when she mistook it for a genuine police box. She quickly became embroiled in the events surrounding his regeneration, and soon found herself a somewhat unwilling passenger of the Fifth Doctor. She was one of the few companions to have parted company with the Doctor, only to return for a significant number of adventures. She was joined in her travels by Adric, Nyssa, Turlough, Kamelion, and, briefly, the Brigadier.
Her relatively long tenure of service onboard the TARDIS belied an ambivalence about wishing to travel with the Doctor. Until her final glimpse of the TARDIS, she vacillated between wanting to stay and wanting to go. She returned to work as an air stewardess in 1985.
Tegan was stubborn, loud, and direct. She once described herself as "just a mouth on legs". While she often bickered with her fellow travelers, her intrinsic honesty and morality proved useful. The Doctor once noted that these qualities made her a good coordinator. She was also more likely to detect a threat to the Doctor's safety than her fellow companions.
Of her fellow travelers, she was likely closest to Nyssa, whose nature was in many ways the precise opposite of her own. Though morally indignant at the Doctor's apparent unwillingness to save Adric's life, she was genuinely saddened when Nyssa left. On Deva Loca, Tegan argued with Adric after he suggested she was too weak minded to defy the Mara, and therefore the ensuing chaos was her fault. Although she seemed to despise violence, she would resort to it under certain circumstances. When the Master threatened the Doctor, Tegan immediately threw a knife at him.
Despite the strong front she adopted, she was actually quite insecure. This manifested itself most strongly in her inability to firmly decide whether she wanted to stay onboard the TARDIS. Even when she seemed most resolute in her determination to go, she quickly reversed herself. On both occasions when she left the TARDIS, it was the Doctor's act of dematerializing the TARDIS — and not her own unwavering desire to go — which firmly separated the two. Seeing through Tegan's false bravado, the Doctor encouraged her to find her inner strength with the words, "Brave heart, Tegan."
